Neutron Radiographic Inspection of Radioactive Irradiated Reactor Fuel Specimens

A method for nondestructive inspection of highly radioactive, irradiated reactor fuel specimens is described. The method is a neutron radiographic technique which employs image detectors of metal screens of silver, dysprosium and indium. After exposing these screens to the neutron image, an autoradiograph of the metal screen is taken to produce the radiographic image. By using this technique, interference on the radiograph caused by the radioactivity of the test objects is eliminated. The image quality yielded by this method is excellent and easily shows fuel deformation and void areas, and other components within the fuel assembly capsule. The advantages of this method over other inspection methods for such materials are described.